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By T M. Campos, J Silva, L M. Tavares, J Lichter, L P. Alves, B K. N Rocha, H D. G Turrer

The depletion of the richest ore deposits and the increase in number of mining projects involving deposits with complex mineralogy, higher competence and lower grade has led to an eminent need for improving understanding on multicomponent behaviour in mineral processing. One particularly relevant case is the ball milling of itabirite iron ores fed to the processing plant of Minas-Rio operation in Brazil. Dealing with the two main mineralogical components of the ore, namely hematite and quartz, the operation faces some challenges to improve understanding on how the two components behave in the process. Mathematical models have showed potential to give support in this task, but its applications to describe this type of industrial-scale grinding is still missing. The present work demonstrates the application of a multi-component ball mill model to simulate a closed ball mill circuit with hydrocyclones using the commercial software Integrated Extraction Simulator (IES). Model was calibrated on the basis of bench-scale tests and industrial surveys. Multi-component simulation results are then compared to those considering a single component in the feed, demonstrating the value and great insights that can be achieved by using the former in optimising plant operation.

Aug 24, 2022

The sole reason for a mine to exist is to extract the finite mineral resource. Accurate grade control is critical to the economics of any mine. If grade control is not optimised, then no matter how good the downstream processes are, the full potential of the operation will not be realised. The detailed implementation of grade control varies but typically consists of sampling and assaying to determine the location of the ore zones. A lot of time, money and effort are spent defining the location of the ore as accurately as possible à but then it is blown up! The effect that blasting has on grade control is rarely adequately accounted for when the rock is excavated because there has never been an accurate and practical method for measuring blast movement. This paper draws on over six years of research into measuring and understanding blast movement, which started at the Julius Kruttschnitt Mineral Research Centre (JKMRC) of the University of Queensland. The research has made a unique contribution to open pit blasting by helping to develop a practical tool for measuring blast movement, which was then used to improve the understanding of three-dimensional blast movement dynamics. However, these achievements would be of largely academic interest without taking the final step of using this technology and knowledge to account for blast movement by translating the ore polygons in response to the measured movement vectors. This paper provides an overview of blast movement but focuses on one site where blast movement was measured during three separate periods, with significantly different orientation of the mineralisation on each occasion. The theoretical ore loss varied from nine per cent to 24 per cent. The differences are primarily due to the orientation of the ore polygons relative to the direction of movement. The optimum grade control solution is a combination of accurately accounting for blast movement and designing appropriate blasts.

Jan 1, 2009

By Jelenich L, Murray J. Rantanen J

The experience gained in the development of an Operator Guidance System (OGS) for on-line process control and fault diagnosis in a commercial scale sintering process will be discussed in this paper. The OGS development started with the specification of feasible control and support tasks, eg ratio control scheme, mass balance calculations. Next, minimum requirements for fault diagnosis and process control were defined and the adequacy of existing instrumentation was assessed. The OGS knowledge base consists of both quantitative and qualitative diagnosis methods. Quantitative models based on fundamental engineering principle are used first and any gaps in such quantitative knowledge are then filled with heuristic rules. The diagnostic rules for the knowledge base was developed based on the knowledge acquired from experienced operators and operations engineers and validated with plant data. A real time reasoning program was written using C language and data base software. The OGS has a human-computer interface which is the primary means of interaction between the OGS and process operator. The OGS development has been successful in assisting operators in decision-making in their routine tasks. Further enhancement to the existing system is currently underway.

Jan 1, 1995

By Phelan JM

Poor selectivity in the separation of two sulphides generally arises because the flotation characteristics of the coarse sizes of the valuable mineral and finer sizes of non-valuable minerals are identical. Separat- ing the pulp into two size fractions at a specifically determined cut size and conditioning each size fraction with its own optimum reagent addi- tion is known to be helpful in improving such selectivity problems. The performance of the zinc section of the complex ore circuit at Wood- lawn Mines has been analysed in detail. The selective recovery of zinc was found to be a problem in zinc/pyrite separation. However, atypi- cally, the separation problem was between coarse zinc and coarse, not finer, pyrite. In spite of this the use of separate conditioning has effected significant improvements in rougher concentrate. Selectivity (and hence grade), overall recovery and flotation rate have all been enhanced. Dis- appointingly, coarse zinc recovery was not increased but, with careful optimization, this might be achieved without sacrificing the gains already realized. The technique of separate conditioning clearly has general application in other circuits where selectivity is a significant problem.

Jan 1, 1988

By H Park, V Sahajwalla

"Due to the increasing amount of gangues in iron ores, a beneficiation process is required more as a preliminary step for ironmaking process. However, mechanical grinding and washing of iron ore needs tremendous effort that increases operating cost. Therefore, there is a necessity of a novel approach to ironmaking which can tolerate considerable amounts of silica or alumina. In the present study, a high alumina-carbon composite pellet was examined for an ironmaking process. The effect of compositional changes in the CaO-FexOy-Al2O3-SiO2 oxide system on the reduction of carbon composite pellets was investigated in a purpose built thermo-gravimetric analyser (TGA) at 1473K (1200¦C). As a result, alumina increased the reaction rate of carbon composite pellets by increasing surface area, while silica decreased the reaction rate by lowering surface area of samples. Infrared gas analysis assisted with the reaction kinetics of carbon composite pellets through measurement of CO and CO2 in off-gases. This study will assist with establishing the new pelletising method which differs from the conventional fluxed pellets.CITATION:Park, H and Sahajwalla, V, 2013. Effect of CaO-FexOy-Al2O3-SiO2 oxide system on the reduction of carbon composite pellets, in Proceedings Iron Ore 2013, pp 467-472 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

The BHP Billiton Cannington mine uses sequential flotation to treat a silver, lead and zinc ore supplied from an underground mine. The final products from the process plant are a silver rich lead concentrate and a zinc concentrate. Operational history of plant performance highlighted that the majority of valuable metal losses to final tailing occurred in the -5 ¦m fraction. Research completed on the flotation characteristics of this size fraction in plant feed resulted in the development of a split flotation process to improve the silver and lead mineral recoveries. Construction of a $A 9.5 million brownfield project to install the new split flotation circuit at Cannington was completed in July 2002. The circuit consists of three stages of cyclone classification to recover the ultra fine material to a final cyclone overflow stream, conditioning of this pulp to achieve optimal process conditions, and conventional rougher and three stage cleaner flotation to produce a silver rich lead concentrate. The rougher tail from the new circuit is recombined with the cyclone underflow streams and processed through the original lead-zinc flotation circuit. This paper discusses the circuit design, material properties, material selection for components of the circuit, operational practices and requirements to ensure the circuit succeeded in meeting production targets. The technology is subject of a number of patent applications including international application No PCT/AU02/00400.

Jan 1, 2003

By T Roberts, S Talu

Steel wire weld mesh is a common industry standard surface support used in underground mining, traditionally installed with mining drills during the bolting cycle. As underground mining depth and stress increase, mining methods and their sequences at these depths place challenges on conventional surface support options. These challenges have provided a need for high capacity surface support options that improve development efficiency, reduce the need for secondary ground support installation and is easily installed with current mining equipment. A 5m2 mesh testing machine was built, suspending a 9500kg concrete slab, designed with multiple hold down points to test varying bolting patterns. Mesh load and displacement is accurately measured using a data acquisition system which pushes against the restrained mesh module with an available 200kN load and 1200mm displacement capacity. A testing program comparing conventional surface support, straps and combinations of both were tested for baseline results. New module designs incorporating existing mesh types and new design concepts were manufactured to allow for single pass installation during a bolting cycle. Nine mesh types, mesh/strap combinations and new mesh module designs were compared using the same test method. Based on these results, two high capacity mesh module types are produced. This paper will detail the test program, load and displacement results and underground mesh module performance, describing the two high capacity mesh modules function within the development cycle and manual handling. CITATION:Roberts, T, Talu, S and Wang, Y, 2018. Design and testing of high capacity surface support, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 303–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

Coal mining ceased at Strongman Mine this year after 70 years of production. Underground mining finished in 2003 and opencast methods began in 1998. During the life of the mine, 8 million tonnes of coal was extracted from two underground mines and 1.2 million tonnes removed through opencast methods. Strongman Mine is within the Grey Coal Fields; various seams have been extracted from the Rewanui Coal Measures. Coal extracted was predominantly of thermal or semi-soft specifications and characterised by low sulphur and low ash.   The area has steep topography, high rainfall (>3000 mm/yr) and is particularly exposed to westerly quarter winds. Strongman 1 and 2 underground mines are located in the steep, narrow valley which leads to the Strongman Opencast at the top of the valley. Subsidence from underground mining combined with spontaneous combustion, has resulted in an underground fire which has had substantial surface effects. Opencast mining in the steep topography resulted in several landslides at the perimeters of the site. These factors, along with water management, topsoil management and erosion control have added to the complexity of rehabilitating the site.   Rehabilitation of the site is well underway, including infrastructure removal, final landform creation and revegetation of the Strongman Opencast footprint (~45 hectares). Some innovative methods of rehabilitation have been trialled. Successful trials such as helicopter-seeding and moss hydro-seeding on highwalls are now routinely used along with traditional revegetation practices. 18 hectares disturbed land has been replanted with 88 000 seedlings, and another 200 000 seedlings are scheduled for planting over the three years. Fire management is an ongoing challenge; however thermal photography shows a steady decrease in hot areas which have been contained by grout curtains.   Mine closure is some time away and will occur after all standards set by Solid Energy and regulatory bodies are achieved.

Jan 1, 2006

'Industrial Minerals - their mining and use in New Zealand' is the theme of the 1978 Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy. This paper describes the use of phosphate rock, sulphur and potassium chloride (potash) - three industrial minerals which have enabled the farmers of New Zealand to increase production to current levels. The growth of imports of these raw materials for the New Zealand fertiliser industry is well documented in NZ Fertiliser Statistics 1977. This is the most recent of the Ministry of Agriculture and Fisheries annual publications on this Subject prepared from the detailed returns of fertiliser manufacture and sales from each fertiliser works. There are now 12 of these works in New Zealand one of the most recently established being in Whangarie where this conference is being held. Its capacity to manufacture superphosphate will shortly be 300 000 tonnes twice that when it opened late in 1964. New grinding and manufacturing equipment comes on stream early in 1979. This paper illustrates the interdependence of two primary industries, agriculture and mining. New Zealand's economy in the foreseeable future will be based on agriculture so that our standard of living is dependent on the overseas prices and freight costs of the bulk raw materials from which our fertilisers are made. For the year ended 31 March 1978 New Zealand's total exports were $3395 million, of this total $2413 million (71%) came from the products of pastoral agriculture (wheat, wool, dairy and other animal products), $291 million from forest products and $501 (15%) from manufactured exports. Approximately half of the pastoral receipts can be attributed to the fertilisers applied at a total cost of about $200 million including subsidy.

Jan 1, 1978

Byproduct coking is practised in three of the major Australian ironmaking centres, the Newcastle and Whyalla works of the Broken Hill Proprietary Co. Ltd. and the Port Kembla works of Australian Iron & Steel Pty. Ltd. Coking first commenced at Newcastle in 1915 and at Port Kembla in 1938. The installations established at these centres include coal cleaning facilities and com- plete byproduct streams. The Whyalla plant, because of its location is somewhat less extensive, having no coal cleaning plant and a comparatively restricted byproduct section. As new batteries have been built every opportunity has been taken to incorporate modern design features and improved operat- ing techniques. This has included the provision of equipment to reduce atmospheric and water pollution. A marked reduction of markets for byproducts has had serious repercussions on the profitability of this section of the Industry.

Jan 1, 1972

With the sinking of the new No. 3 Shaft and the increasing depth and northward movement of the mining operations, improved ventilation of the mine workings became necessary and it was decided to sink a new upcast ventilation shaft midway between No. 2 Shaft and No. 3 Shaft.The shaft is finished to 16 ft. internal diameter and connects with the mine workings at the 2,600-ft. level. It is lined with unreinforced Concrete approximately 12 in. thick. The shaft sinking routine was drilling, blasting and mucking by hand using a 27-cub. ft. capacity bucket. The concrete lining was poured in conjunction with the sinking and was normally finished within 30 to 50 ft. of the shaft bottom.

Jan 1, 1957

Sulphide Corporation Pty. Limited operates a Lead/Zinc Smelter at Cockle Creek, some 11 miles from Newcastle, N. S. W . Works effluents totalling some 8, 500, 000 gallons/day join Cockle Creek some 1. 8 miles from its mouth in the most northerly section of Lake Macquarie, The Creek is also the source of the Works cooling water intake of which approximates 8, 000, 000 g.p. d. In view of the wide use of the Lake for recreational activities by the people of Newcastle and the surrounding areas, particular care must be taken to ensure that the control of effluent quality is of a high order. This paper outlines the philosophy and measures taken for the treatment and control of plant effluents discharging into Cockle Creek.

Jan 1, 1971

By H Hy÷tyniemi

In this paper multivariate data analysis performed on a new multi-camera system implemented to zinc flotation circuit of PyhSsalmi mine is presented. Image-analysis-based system was developed to take advantage of the commonly known fact that the changes in the flotation process are reflected to the visual appearance of the froth surface. Most often the changes are seen first in the froth and later in other process measurements. The image variables are already utilised in closed loop control and considerable savings are achieved with the current setting, but the results coming from the separate cells are used individually. This is clearly not the optimal way to take advantage of the many measurements coming from different locations of the process. A better approach would be for example to use the measurements coming from the early stages of the process to predict the behaviour (or improve the quality of measurements) in the later stages. The methods described in this paper are aimed to improving the situation in this sense.

Jan 1, 2005

The purpose of this paper is to outline the equipment used for diamond drilling at Mount Isa, together with alterations and recent improvements therein. As the majority of the drilling is carried out with machines running at relatively high speeds using XRN blast hole bits, the paper is mainly devoted to this branch of drilling.Because diamond bit costs constitute the major expense, a considerable amount of research into bit design has been carried out, and in several instances, costs per foot have shown an appreciable decrease in spite of rising manufacturing costs and higher diamond prices. Equipment performance has at times been erratic due to delays in delivery and occasionally because of faulty parts, but in general the position has improved by keeping in close contact with the manufacturers.BLASTHOLE DRILLING MACHINESThe standard blasthole diamond drill is the 'E-500' two cylinder air powered model manufactured by Mineral Drillers Limited. Several of the older pattern JV41 are still in use, but are being retired as they wear out.. Machines are repaired in the underground diamond drill shop.The normal feed gears used when drilling in lead shales are 350 top gear and 450 low gear-actually 357 and 438 revolutions per inch of advance respectively. The 300 gear was commonly used several years ago, but it was found that bit footages could be increased without any appreciable drop in penetration rate by reducing to the 350 gear. Gears used for copper drilling are 650 and 750. Footage per shift...

Jan 1, 1953

Woodlawn Mines began underground operations in 1986. At the time of going underground it was envisaged that there would be no 'contract' payment to the underground employees. This was a relatively unique step to make, especially as most major underground mines in Australia relied heavily on the contract system to motivate their workforce. (Obviously with varying degrees of success.) Woodlawn faced the task of motivating their employees through a multi-skilled system with a great emphasis on leadership and a genuine care for their employees. The 'proof of the pudding' is that Woodlawn has not lost any time over industrial issues since beginning underground operations in 1986. To achieve success in any operation the organisation must not only be advanced in its management principles but also be prepared to be innovative in the way it deals with physical problems, ie ground control, equipment selection and maintenance. Difficult ground conditions at Woodlawn have necessitated the deployment of two Cabolt Jumbos and the construction of cost-effective shotcrete systems. The shotcrete system now being built has been tested in a prototype form and is proving to be a safe and simple way to manage weak, low stress friable ground. Although the ground at Woodlawn has low stress component by virtue of the fact the ore can have a density of 4.5dm3, cable dowelling has become a necessity. The two cable dowel jumbos install high quality reinforced cables. The pressure of 'production' means that these machines must be consistently available for use and the training of maintenance personnel and operators ensures that a maximum of cable dowels can be installed over any given time span. In any modem mine ventilation is a primary concern and the major area of concern comes from the vehicles themselves. In our recent replacement for the standard 'Toro' loader, three engine options were considered. A relative newcomer to underground mining was accepted. The Detroit 60 series (DDEC) engine came with a great reputation and has lived up to this. The engine has an electronic management system that reduces particulates to a hardly visible minimum, provides great amounts of engine power and reduces fuel consumption by approximately 45 per cent. The operational benefits of such an engine are worth sharing through this conference.

Jan 1, 1995

Field investigation of surface subsidence events associated with both active and abandoned underground coal mines in the United States has established criteria that enable the prediction and classification of mine-related subsidence. The key was establishing the role of geology in all types of subsidence and the recognition of beam subsidence in specific geologic settings. The classification is based on overburden thickness, variations in stratigraphy, topography and mine plan. Types of subsidence are Pit, Room, Sag, and Beam. Pit subsidence is associated with three geologic settings: shale overburden, seasonally wet unconsolidated overburden, and perched water table in unconsolidated overburden. Room subsidence occurs where the roof across the width of the room fails to the surface and a shallow depression develops.

Jan 1, 1992

By Y Durkheim, P Saunier, L Ameglio

"In the last decade Afitex developed the Draintube™ geocomposite, which provides simultaneous drainage and waterproofing functions. This new type of drain tubes planar geocomposites (DTPG) differs from other geocomposites as the drainage core is composed of multiple corrugated and perforated pipes instead of biaxial or triaxial nets. It is furthermore associated with needle-punch stitched layers of non-woven geotextiles, which act either as capillary mediums or as filters.In this paper, the structure of the Draintube™ drainage composite is presented along with its key properties and the drainage mechanism associated with its particular structure.The relevance of this kind of structure is then reviewed based on past and current laboratory bench evaluations and field installations for mining applications such as the covering of acid rock drainage (ARD) tailings for the Central Manitoba Mine (Canada) site-rehabilitation; and as a pregnant solution collection layer in heap leach pads.Some of the demonstrated critical advantages of Draintube™ in the mining industry are as follows: reduction of the thickness, hence lower volume of granular drain layers improvement of fluid and gas collection and reduction of the hydraulic load reduction of secondary collector network mechanical protection of the sealing membrane fast and economical installation of interlifts stability under extreme conditions (compression, temperature, pH) increased stability of entire covering system and reinforcement of protection of dykes filtration of the covered material customised drainage positive connection of the geocomposite to collector pipes enable leaks detection (using a conductive textile layer) with an electrical test.CITATION:Saunier, P, Ameglio, L and Durkheim, Y, 2015. Tubular drainage and lining geocomposite for mine tailings and heap leach pads, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 297–304 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 27, 2015

By S Morgan, D J. Bradshaw, S Schwarz

The characterisation of the flotation kinetic response in future mining deposits is important because the flotation response is affected by changes in ore mineralogy. Current methods for characterising the flotation response of different ore types, such as the JK floatability index test (JKFIT) methodology, require at least 10 kg of feed material. In geometallurgical applications, this material is taken from core samples. Core samples are generally obtained using specialised drills and are limited in nature. Thus, it would be beneficial to develop a laboratory technique that required less sample material but still characterised the flotation response of different ore types. The JK mineral separation index (JKMSi) is a small-scale flotation test that requires significantly less feed material (10 g of sample/data point). This study aims to investigate the JKMSi system kinetics and to validate this technique using the JKFIT proven methodology. The JKMSi flotation kinetics were manipulated by varying selected system parameters. The relationship between these parameters and mineral recovery was used to obtain floatability characteristics of the ore. For an ore sample containing chalcopyrite and pyrite, it was found that the chalcopyrite floatability parameters determined from both the JKMSi and JKFIT tests were of the same order of magnitude and the mass fractions of the fast, slow and non-floating components were similar. For pyrite, the floatability parameters were not of the same order of magnitude, but modifications to the test procedure have been identified, which may correct this.CITATION:Morgan, S, Bradshaw, D J and Schwarz, S, 2012. Julius Kruttschnitt Mineral Separation Index - Small-scale test to characterise the flotation response of an ore type, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 159-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The papers to be presented in this Session show an interesting range of subject matter. Three discuss specific problems associated with existing mines, one deals with hydrogeological risk evaluation and one uses the impact of mine drainage on an aquifer to analyse a large-scale hydraulic parameter. Paper 1. Environment studies to determine the impacts of re-opening Banska Stiavnica-Hodrusa ore district in Czechoslovakia - Dusan Cababla - Marian Skaviniak. Future developments in established mining areas may have significant hydrogeological implications, especially where the existing mines are to be deepened. In turn this may have an impact in the area of the disposal of ever larger quantities of mine water, particularly, as is often the case, where the quality of this water is poor.

Jan 1, 1988

By K Osman, P Bennett

The mining of an underground orebody requires development both in waste and ore before stoping commences. Regardless of what metal is being extracted, the waste development is minimised to reduce the cost per unit of metal mined. At the Western Metals Zinc Kapok mine site, reducing the cost per tonne of lead and zinc mined is paramount. Decline waste development costs can be minimised by methods such as increased gradient or reduced drive size. Ore development will also involve some mining of waste. The degree to which waste mining can be minimised will depend on the thickness and dip of the orebody. The drive geometry will also determine the percentage of waste within the face. It is by mining methods such as resue mining that selective mining may be used to maximise the amount of metal mined and reduce waste dilution. Resue mining can be used around a set of selection criteria established by the mine site. These selection criteria will determine how resue mining can be applied to the mine site. Selection criteria include firing times, number of headings available, acceptance criteria for percentage lost metal, dilution and most importantly operator acceptance. The single pass or two pass resue mining method should be chosen depending on the site acceptance criteria and selection criteria. The Western Metals Zinc Kapok mine site has established a set of parameters which accept the two pass resue mining method for the mining of the ore drives. The blasting results from a single pass resue method were reviewed during more recent trials in a single heading. Through a comparison of results, the parameters allowed the decision to determine the applicability of resue mining and its current form to Kapok. This paper outlines the parameters set by the Kapok mine site, reviews these in relation to the two forms of resue mining and examines the criteria which make this mining method applicable for Western Metals Zinc.

Jan 1, 2002